1. Field of the Invention
The present invention relates generally to packaging for surgical devices, with particular application for packaging a surgical device for placing a suburethral sling to treat urinary incontinence.
2. Background Discussion
Women account for more than 11 million of incontinence cases. Moreover, a majority of women with incontinence suffer from stress urinary incontinence (SUI). Women with SUI involuntarily lose urine during normal daily activities and movements, such as laughing, coughing, sneezing and regular exercise.
SUI may be caused by a functional defect of the tissue or ligaments connecting the vaginal wall with the pelvic muscles and pubic bone. Common causes include repetitive straining of the pelvic muscles, childbirth, loss of pelvic muscle tone, and estrogen loss. Such a defect results in an improperly functioning urethra. Unlike other types of incontinence, SUI is not a problem of the bladder.
Normally, the urethra, when properly supported by strong pelvic floor muscles and healthy connective tissue, maintains a tight seal to prevent involuntary loss of urine. When a woman suffers from the most common form of SUI, however, weakened muscle and pelvic tissues are unable to adequately support the urethra in its correct position. As a result, during normal movements when pressure is exerted on the bladder from the diaphragm, the urethra cannot retain its seal, permitting urine to escape. Because SUI is both embarrassing and unpredictable, many women with SUI avoid an active lifestyle and shy away from social situations.
One device and method for placing a sub-urethral sling is described in detail in U.S. Pat. No. 5,899,909. This patent discloses a surgical instrument comprising a shank having a handle at one end and connecting means at the other end to receive, one at a time, two curved needle-like elements which are connected at one end to one end of a mesh intended to be implanted into the body. In practice, the mesh is passed into the body via the vagina first at one end and then at the other end, at one side and the other, respectively, of the urethra to form a loop around the urethra, located between the urethra and vaginal wall. The mesh is extended over the pubis and through the abdominal wall and is tightened. The mesh ends are cut at the abdominal wall, and the mesh is left implanted in the body. This trans-vaginal procedure is exemplified by the TVT product sold by the Gynecare franchise of Ethicon Inc., a Johnson & Johnson Company, of Somerville, N.J., USA. In this procedure two 5 mm needles pass a PROLENE mesh trans-vaginally and through the abdomen to create a tension-free support around the mid urethra.
Sub-urethral slings have also been place by a different approach, wherein a needle is passed first though the abdominal wall, along the same path as described above, and eventually exiting through the vaginal incision. The tape is then coupled to the needle in some manner, and pulled back through the body from the vaginal incision and out through the abdominal incision. The chosen approach, vaginal or abdominal, will often depend on the preferences of the surgeon.
Yet another approach for implanting a sub-urethral sling has also been recently developed. In a “transobturator” approach, the implanted sling extends from beneath the urethra, and out through the obturator hole on either side. The procedure may involve inserting an appropriately configured needle from a vaginal incision and subsequently out through the obturator hole, or vice versa. The former technique (an “inside-out” approach) has been performed using a surgical instrument substantially similar to that shown in FIG. 1. This instrument is described in greater detail in copending U.S. patent application Ser. No. 10/699,045, which was filed on Oct. 31, 2003 and entitled “Guide for Surgical Device for the Treatment of Urinary Incontinence”, and Ser. No. 10/706,559, which was filed on Nov. 12, 2003 and entitled “Improved Surgical Instrument and Method for the Treatment of Urinary Incontinence,” which are incorporated herein by reference in their entirety. The surgical instrument or assembly 100 includes two needle assemblies 114, 116 that include two surgical passers 101, 103 that are secured at proximal ends to handles 102, 104. The surgical passers are curved and form a somewhat helical shape, and are mirror images of one another so that one 101 is particularly suited for passage through the body on the left side of the urethra, whereas the other 103 is particularly suited for passage on the opposite (right) side of the urethra. The needle assembly further includes tube elements 106, 108 that are removably applied over the ends of the surgical passers. Proximal ends of the tube elements are coupled to the tape 110 to be implanted as a sling beneath the urethra. The tape is preferably of knitted mesh construction, such as Prolene® polypropylene mesh (manufactured by Ethicon, Inc. of Somerville, N.J.) having dimensions of approximately ½×18 inches. The tape is also preferably covered by a plastic sheath that overlaps in the middle section so as to be easily removably. The surgical assembly may also include a guide element 112 to help guide the needle assemblies through the patient's body and to ensure safe passage thereof.
To implant a sub-urethral tape using the surgical assembly described above, the patient is first placed in the dorsal lithotomy position with the hips hyperflexed over the abdomen, and the bladder emptied. Next, the exit points of the surgical needles through the obturator foramen are marked. A midline incision is then made in the vaginal mucosa, and the left and right sides dissected with scissors or the like until it reaches and dissects the obturator membrane. The guide element 112 is then inserted through the vaginal incision and into the dissected tract until is passes the inferior pubic ramus and enters the opening previously made in the obturator membrane.
Once the guide element is fully inserted on one side as described above, the surgical passer 101 with associated tube element 106 (the needle assembly) for that side of the body is then inserted. The assembly is positioned within the guide member and passed through the dissected tract following the channel of the guide element from the vaginal incision and through the obturator membrane. Once the tip of the assembly traverses the obturator membrane, the guide element is removed. The assembly is rotated the remainder of the way through until the tip emerges from the skin at the exit point. The end of the tube element is then grasped, and the surgical passer reverse rotated to bring it back through the dissected tract and out through the vaginal incision. Subsequently, the tube element is pulled through the skin incision until the tape 110 exits the skin incision. The process is then repeated on the patient's other side and the tape adjusted, leaving the tape to form the sub-urethral sling beneath the mid-portion of the urethra.
When it comes to packaging the surgical assembly described above, several challenges have been encountered. First, the needle assemblies are each designed for passing the tape through one specific side of the body and on one side of the urethra. Further, they are specifically designed for passing the tape from the vaginal incision and out through the obturator foramen, or an “inside-out” approach. In other words, a given needle is designed for use on one side of the body in one direction, such that a needle for use in passing the tape on the left side would be different depending on whether using an “inside-out” or “outside-in” approach. Thus, it is important that during transition from the packaging during surgery, there is limited room for opportunity for mixing up the needles. The transition and presentation should best ensure limited entanglement of the tape, and that all elements remain sterile. An additional concern is for the guide element, as it is used prior to inserting the first needle, and then again prior to inserting the second needle. A convenient way must be available to ensure sterility between uses.
Another packaging concern is ensuring that the tube elements, which are assembled over curved helical needles of opposing pitches, are not jostled relative to the needle, which would require re-assembly prior to use. Yet another packaging concern is ensuring that the sheath and mesh assembly is not kinked or damaged during storage or transit, as damage thereto could render the device inoperative. Further, it is important that the packaging and other device elements not be damaged by the sharp tip of the tube elements, and that the sharp tip itself not be damaged. The packaging according to the present invention overcomes these challenges, as well as provides a means by which to cleanly and efficiently present the surgeon with the instruments needed for performing the surgical procedure.